Kenosha harbor, Wisconsin and shewing the state of the channel between the U.S. piers and the bar from survey made, as above, between the 8th & the 12th of May 1857 / from survey made in December 1854 by assistant John R. Mayer, under the direction of Brevet Lieut. Col. J.D. Graham, Major, U.S. Top. Engineers. Superintending Engineer of Lake Michigan Works.